1. Field of the Invention
The present invention relates to systems and methods for controlling regeneration of a particulate filter by fuel delivery to an oxidation catalyst.
2. Background Art
A particulate filter is a device for capturing particulates emitted in exhaust gases from a combustion engine. In some systems employing a particulate filter, it may be desired to oxidize or burn the captured particulates in a process commonly referred to as regeneration. This is desirable to reduce the restriction of the particulate filter on the exhaust flow and thus maximize the engine fuel economy. The burning of the particulates is dependent on temperatures at the particulate filter. The high temperature needed to regenerate the particulate filter is typically achieved by vaporizing unburned fuel in the exhaust gas by means of a fuel doser and the resultant fuel/exhaust gas mixture then flows to an oxidation catalyst where it is burned to heat the exhaust gas. This process is influenced by exhaust gas fuel levels and/or exhaust gas temperatures.
Accordingly, a need exists to eliminate the doser and control exhaust gas fuel levels and/or exhaust gas temperatures at the oxidation catalyst so as to facilitate burning of particulates captured with the particulate filter.